On any given day, standing in the parking lot of Northway Mall near downtown Anchorage, passerby can stop and see small planes -- Cessnas, Supercubs, Navajos and others -- flying east to west, coming in for a landing on Merrill Field right across the street. Often, they're flying so low it can make an observer nervous, worried about the trees just outside the fence of the airfield. So when a hulking Boeing 727 cargo jet, being decommissioned by FedEx and donated to the University of Alaska Anchorage's aviation maintenance program, landed at the airfield on Tuesday, it may have alarmed a few people.

Most, however, were already aware of this special event; the plane was only able to land with special permission from the Anchorage Assembly, due to its unique size for the airport, which was designed for those smaller, general aviation aircraft. With the plane due to land at 2 p.m., the parking lot of the mall was already filling up by 1:30, with tripods set atop snowberms and curious onlookers awaiting the plane's arrival. Traffic began to back up on Merrill Field Drive as police directed cars past already-full parking lots. Observers stood along the airport's edge, some with their hands loosely hanging from the chainlink fence and their faces pressed up close, like children at a zoo.

Read More: Unusual 727 landing at Anchorage's Merrill Field draws a crowd